Down feathers:
- Down feathers are soft and fluffy, and they help provide insulation for birds.
- They have a loose structure with many barbs that trap air, creating a layer that helps to keep the bird warm.
- Down feathers are usually found in the inner layer of a bird's plumage.
- They lack the interlocking barbules that contour feathers have, which gives them their characteristic fluffy appearance.
Contour feathers:
- Contour feathers are firmer and more structured than down feathers, and they serve primarily as a protective covering for the bird's body.
- They have a more compact structure with closely interlocked barbules, which gives them a smooth and streamlined appearance.
- Contour feathers are found in the outer layer of a bird's plumage and help to create the bird's overall shape.
- They also play a role in waterproofing, providing some protection against water and moisture.
In summary, down feathers are responsible for insulation, while contour feathers provide protection, waterproofing, and shape to a bird's body.